In a manufacturing process of a semiconductor device, plasma etching has been performed to form a circuit pattern by using a resist patterned by a photolithography technology as a mask. In the 45 nm CD (Critical Dimension) generation, an ArF resist has been used as a mask to keep up with miniaturization, but the ArF resist has a disadvantage of low plasma resistance. As a way to resolve this problem, there has been employed a method called a dry development using a multilayer resist which is formed by stacking a SiO2 film and a plasma-resistant resist underneath the ArF resist. In the generation in which miniaturization has been progressed further than the 45 nm generation, the film thickness of the ArF resist is reduced to 200 nm, so that this thickness serves as a basis of the dry development. That is, a thickness of SiO2 film capable of being plasma-etched by using the resist film of such thickness and a thickness of the lower resist capable of being plasma-etched by using the SiO2 film of such thickness are about 300 nm. However, when the lower resist has that thickness, it is impossible to obtain a sufficient plasma resistance with respect to the film thickness of an etching target, thus resulting in a failure to accomplish an etching with a high precision. For this reason, there has been a demand for a film having a higher etching resistance as an alternative to the lower resist film.
Meanwhile, Patent Document 1 discloses a method of using an amorphous carbon film, which is deposited by CVD (Chemical Vapor Deposition) while using a hydrocarbon gas and an inert gas, as a substitute for the SiO2 film used in the multilayer resist or as an anti-reflection film. An attempt to use the amorphous carbon film for the above-mentioned purpose is considered.    Patent Document 1: Japanese Patent Laid-open Publication No. 2002-12972